Various methods of mapping dispersion in optical networks are known in the art.
US2010329695A relates to dispersion slope compensation and dispersion map management systems and methods in an optical network utilizing a reconfigurable optical add-drop multiplexer (ROADM) with a plurality of different values of dispersion compensation modules (DCMs). The DCMs form a dispersion compensation ladder at certain intermediate nodes in the optical network to provide dispersion slope compensation and dispersion map management. The reconfigurable routing structure of the ROADM enables these intermediate nodes to route individual wavelengths to any one of the DCMs as required for the particular path of the wavelength. The solution removes the requirement for banded compensation at receiver nodes and allows for dispersion map management at intermediate points along a fiber route.
The solution requires dispersion map management at intermediate nodes, thus it requires knowing trails in advance, which is problematic in mesh networks.
US2008069573A configures an all-optical network such that at least eighty percent of optical fiber spans of a portion of a first all-optical path of the network have substantially a first residual dispersion per span and at least eighty percent of optical fiber spans of a remainder of the first all-optical path have residual dispersions per span substantially differing from the first residual dispersion per span. The remainder of the first all-optical path includes an overlap between the first all-optical path and a second all-optical path of the network. The second all-optical path has a plurality of optical fiber spans and a substantially singly periodic dispersion map.
Though speaking about overlapping trails in a mesh network, the above solution offers the method that depends on knowing the trails in advance, ahead of time.
US2007183711A describes how Dispersion may be managed in a branched optical network by using transmission segments having a single period segment dispersion map. One or more of such segments may be coupled to network nodes such as terminals or branching units such that dispersion may be managed even when the network is reconfigured. In one embodiment, a single period segment dispersion map provides dispersion compensation at the ends of the segment. In another embodiment, a single period segment dispersion-map provides dispersion compensation at the middle of the segment.
There are some known approaches how to map dispersion in a network serving for conveying traffic at a specific bit rate.
For example, the article “Analytical description of cross-phase modulation in dispersive optical fibers”, M. Shtaif, Optics Lesteres, vol. 23 (1998) discusses requirements to chromatic dispersion in 10G networks.
The work “Reduction of intrachannel nonlinear distortion in 40 Gb/s based WDM transmission over standard fiber”, R. I. Killey et al., IEEE Photon. Tech. let. Vol. 12 (2000) discusses ways of dispersion management in 40G networks.
To the best of the Applicant's knowledge, neither of the prior art references describes how dispersion can be mapped so as to minimize non-linearity impairments in a mesh network, that simultaneously supports traffic at two or more different bit rates which require different and contradicting approaches for dispersion compensation.